Overview of Mechanical estimating

Process and data

Noel Susskind

March 2003

The Bidding Process: Use the spreadsheets

 Spreadsheets (Excel or equivalent) as a stand-alone system for estimating is ubiquitous in mechanical and electrical contracting.  Making a “master template”, and then customizing it for each project bid, is common practice in the business.

 Many estimators add side lookup tables to their spreadsheets to automatically insert labor and materials values that they use repeatedly. Although it is a little more effort to build, it’s relatively easy to use tables of crew labor and materials, and it then becomes a time saver on subsequent bids.  Building tables from scratch can be tedious, so transforming or adapting existing tables from third sources is desirable.  These sources of data are a future opportunity to add extra depth to our data.    Many software applications have some kind of data importing wizardry available.   (This subject of data interoperability is so big, it is going to be another chapter.) 

Estimators sometimes insert labor and materials prices into the spreadsheet tables manually, line-by-line, item-by-item, as the prices of equipment or materials are discovered or quoted to us.

 The main task of the estimating process is the plan takeoff.

The most labor-intensive procedure of “plan and spec” estimating is the quantity take-off.  Various software vendors have created products for  this to be done more quickly.   Much time is spent in taking pipe and sheetmetal quantities off the plans but the aim is to be fast and accurate.  My employer has a variety of estimators with technical expertise in two or three different software environments, for the separate trades of sheetmetal, pipefitting and plumbing.  Some are using Excel and light pen, others are using old- fashion plan- measure wheels with pencil and paper.   It works because they know who is best at each of the trades.

The next most labor-intensive part of the process is gathering price quotes for the equipment and fixtures shown on the bid drawings and specifications.  More time and effort is taken up in communicating with a wide variety of vendors.  This increases the response time and overhead costs.  This could, be reduced, if not eliminated, by better data information systems. 

I had many reasons for investigating outside sources of cost information.  When I began developing an overview of the data sources in the mechanical contracting business, I quickly discovered how fragmented the field is.  Mechanical contracting is basically construction:  a mature industry and a lot of tradition is built into the practice of takeoff and estimating.   The world wide web was an enormous help in reducing the amount of time needed to research this article.  I tried to condense this for the purposes of this report: it is not "exhaustive".  I have also only focused on commercial contracting and have only included a sampling of the residential industry as an aside. 

Quickpen is our major takeoff software:  the software vendor tries to be adaptable to the contractors work by using specifications as a basis.  In other words, they recognize that mechanical contracting has a diverse population of users and end uses.  They have partnerships with 3d CAD software vendors Autodesk and NavisWorks, CAM (plasma cutters) vendor Lockformer.  Quickpen also partners with a variety of price publishing services such as Harrison Publishing House (the Bradford Price book for plumbers and the National Mechanical Contractors Estimator handbook, among others).

It would be logical to incorporate this data into the bidding estimates upfront, but contractors typically cannot get the data in a format they can use.  Most mechanical data vendors, at least the ones I found in 2004, did not supply the know-how or tools by which to migrate or translate their data.  Using the MCAA information in our system of estimating spreadsheets was strictly manual. It was a matter of judging the labor according to professional judgement and experience.